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grace

grace is a tool for monitoring and annotating syscalls for a given process.

It's essentially a lightweight strace, in Go, with colours and pretty output.

It's possible to tweak and filter the output to make it quite readable, for example (using -vnmx):

You can also review a summary of encountered syscalls (and sort by various columns):

grace vs. strace

grace isn't meant to compete with strace, it's purely meant to be a user-friendly, lightweight alternative. However, the following should provide a rough idea of what is supported in grace so far.

Over time grace is meant to become a simpler, more readable alternative to strace (strace for dummies?), albeit with reduced functionality/advanced features.

Feature grace strace
Start a program and print all syscalls it makes
Attach to an existing process by pid and print all syscalls it makes
Filter syscalls by name, e.g. only show occurrences of the open syscall
Filter syscalls using a given path, e.g. only show syscalls that access /etc/passwd
Dump I/O for certain file descriptors
Count occurrences and duration of all syscalls and present in a useful format
Print relative/absolute timestamps
Tamper with syscalls
Print extra information about file descriptors, such as path, socket addresses etc.
Print stack traces
Filter by return value
Pretty colours to make output easier to read
Lots of output options and customisation vectors
Output to file
Filter by failing/non-failing syscalls

NOTE: Please feel free to add important strace features to this table, I'm working with a limited knowledge of strace.

Installation

Grab a statically compiled binary from the latest release.

Supported Platforms/Architecture

Currently only Linux/amd64 is supported. Other architectures coming soon.

If you'd like to implement a new architecture, you can duplicate tracer/sys_amd64.go and convert it to contain the syscall definitions for your arch.

Usage Examples

Trace a program

grace -- cat /dev/null  # replace 'cat /dev/null' with your program

Trace an existing process

grace -p 123 # replace 123 with your pid

# e.g. you could use pgrep to find the pid of a process
grace -p `pgrep ping`

Trace a program and filter by syscall name

grace -f "name=openat" -- cat /dev/null 

# you can also look for multiple syscalls
grace -f "name=openat&name=close" -- cat /dev/null

Trace a program and filter by syscall name and path

grace -f "name=openat&path=/dev/null" -- cat /dev/null

Trace a program and wire up stdin/out/err with the terminal

grace -F -- cat

Trace a program with maximum readability options

grace -vnmx -- cat /dev/null

Trace only failing syscalls

grace -Z -- cat /dev/null 

Show a summary of syscalls with durations, counts and errors

grace -S -- cat /dev/null

Build Dependencies

If you want to build grace yourself instead of using the precompiled binaries, you'll need a recent version of Go (1.19+). Then make build is your friend.